要 旨 ：
We analyze dynamic effects of broken parity in various liquid
crystalline phases. Topics covered include Lehmann-type effects as well as inverse Lehmann-type effects, which can be used as a microscopic pump [1]. Recently we have demonstrated that such effects can also arise in liquid crystalline systems made of achiral molecules provided the overall structure has macroscopic chirality [2]. In such a situation we predict that Lehmann-type effects as well as rotatoelectricity are possible [2].
Over the last few years it has become clear that octupolar (tetrahedral) order could come into play for various types of
nematic liquid crystal phases. We investigate the resulting
macroscopic behavior of non-polar tetrahedral nematic liquid
crystals [3,4] and discuss ambidextrous chirality versus
ambidextrous helicity for nonpolar nematic phases of sufficiently low symmetry [5].
Using these results we make contact with selected recent
experimental results. For Lehmann-type effects we analyze
experimental results on free-standing chiral smectic films [6]. We also critically compare our analysis with reports of octupolar nematic order in at least two different systems [7,8]. Quite remarkably previous experiments also indicate the presence of octupolar order [9,10].